The prior art is replete with mechanisms for feeding a document into a predetermined position on a glass platen. In U.S. Pat. No. 3,844,552, an endless rubber belt is supported between two rollers, with one of the rollers driven by a drive source which includes a motor, gears, etc. The other roller is freely rotatable. Such feed mechanisms have been widely used as document feeders for copying machines. In such mechanisms, a wide rubber belt, which exhibits a high coefficient of friction, contacts the glass platen during an initial period of document feed, and causes a loss of power. To drive the rubber belt and overcome the power loss, a relatively powerful drive source is required. As a result, the size and weight of the feed mechanism is large, and its cost is high.
Small size and low cost image scan apparatus's have been developed for imaging documents. However, large and costly feed mechanisms are not suitable for such devices.
Accordingly, it is an object of this invention to provide an improved document feeder for an image scanner.
It is another object of this invention to provide a low cost, low energy consumption, document feeder.